Excavating machine



Oct. 29, 1963 v. s. PENOTE EXCAVATING MACHINE 2 Sheets-Sheet 1 FiledNov. 6, 1961 INVENTOR. ViNceu'r S. PENOTE 75w, $130 Te ll TT N zys Oct.29, 1963 v. s. PENOTE 3,108,387

EXCAVATING MACHINE Filed Nov. 6, 1961 2 Sheets-Sheet 2 CONTROL VR LVEBHNK j 4 4 INVENTOR.

VI'NCENT S. PENOTE BY 275m 351 1 TM I nrromsys United States PatentOfiice 3,168,337 EXCAVATING MACHENE Vincent S. Penote, Shaker Heights,Ohio, assignor to The Cleveland Trencher Company, Cleveland, Ohio, acorporation of Ohio Filed Nov. 6, 1961, Ser. No. 150,359 6 Claims. (Cl.379()) This invention relates in general to excavating machines, andmore particularly to a digging line tensioning device for excavatingmachines.

In the pending United States patent application of Vincent S. Penote andHenry L. Meyer, Serial No. 94,025, filed March 7, 1961, there isdisclosed an excavating machine comprising a generally horizontallyextending boom with a bucket equipped endless digging line movablymounted on the boom by means of spaced rotatable means, includingwheeled trucks, supported by the boom. It has been found that duringexcavating operations, sometimes a rock or other obstruction becomeslodged between the digging line and the rotatable means or wheels, whichcauses an increased tensioning of the digging line, and may stall thedigging unit, or even cause failure of the digging line chain.

The present invention provides a novel digging line tensioning mechanismwhich is operative to maintain the digging line under a predeterminedtension during normal operation of the excavating machine, but whichincludes means for automatic release of the tension when the tension inthe digging line exceeds a predetermined amount, such as may occur whena rock or the like becomes wedged between the wheeled trucks of thedigging unit and the digging line.

Accordin ly, an object of the invention is to provide a novel chaintensioning device for an endless digging line of an excavating machine.

Another object of the invention is to provide a fluid powered tensioningdevice, for use with the digging line of an excavating machine, whichdevice is operable to effectively tension the digging line, but whichincludes means for releasing the tension, when the latter exceeds apredetermined maximum.

Another object of the invention is to provide a novel tension ng devicefor the digging line of an excavating machine which device is rugged inconstruction, and which may be readily applied to existing excavatingmas chines, or which can be conveniently embodied in new excavatingmachines.

A still further object of the invention is to provide an excavatingmachine having an endless bucket equipped digging line mounted on themachine by means of rotatable members, and including a .tensioningdevice coacting with the rotatable members for maintaining apredetermined tension in the digging line.

A still further object of the invention is to provide a fluid poweredsystem for a tensioning device for the digging line of an excavatingmachine, which may be readily coupled to an existing lluid poweredsystem of an excavating machine, for operating the tensioning device.

Other objects and advantages of the invention will be apparent from theforegoing description taken in conjunction with the accompanyingdrawings wherein:

FIG. 1 is a side elevational, partially broken, generally diagrammaticview of an excavating machine embodying the tensioning device of theinvention;

FIG. 2 is enlarged, fragmentary, side elevational View of the tensioningdevice of FIG. 1;

FIG. 3 is a sectional view taken generally along the plane of line 33 ofFIG. 2, looking in the direction of the arrows;

FIG. 4 is a schematic showing of a fluid system which Patented Get. 29,1%63 2 may be expeditiously utilized for actuating the tensioning deviceof the invention, and which may be readily coupled into an existingfluid system conventionally utilized on excavating machines.

Referring now again to the drawings, and in panticular to FIG. 1thereof, there is illustrated an excavating machine embodying theinstant invention. Such an excavating or trenching machine broadlycomprises a main frame 10 supported on suitable tractor treads 12, amain power plant or internal combustion engine '14 supported on theforward end of the frame 10, a structure 16 for supporting a verticallymovable boom 18 mounted adjacent the opposite end of the vehiclechassis, and an endless bucket equipped digging unit 20 movably mountedon the boom structure and drivingly connected to the motor unit 14 ofthe machine. The digging line 22 of such digging unit 20 isconventionally formed from endless stretches of transversely disposedchain links which support the buckets 24 thereon, and with such digginglines being movably mounted on rotatable members including wheeledtrucks 26, 26a supported by the boom 18. The digging unit may be of thegenerally inverted triangular shaped configuration in side elevationillustrated, and may be driven by drive drum 28.

Transversely spaced wheels 32 of truck 26a may be rotatably mounted on ashaft 36 extending transversely of the boom 18, with the shaft beingmounted adjacent its ends in bearing blocks 38 mounted in elongatedslots 49 in transversely spaced housing or bracket members 42, securedto the corresponding end of the boom structure 18.

Referring now to FIG. 3, each of said bearing blocks 33 preferablyembodies flange means 44 thereon which overlap confronting portions ofthe associated housing 42, and thereby are retained in alignment in saidhousing, but are permitted reciprocal movement in the housing. A fluidpowered ram 48 is secured at one end, such as 50, to the boom structure18, and with the other end, such as the outer end of the piston rod,being attached to the corresponding bearing block member 38.

Hydraulic or fluid powered systems are conventionally utilized onexcavating machines in present day practice, to actuate variouscomponents of the machines, such as for instance, the unloading conveyormechanism 52, both for driving the conveyor and for shifting ittransversely of the machine and through the digging unit, and thus theremay be conventionally provided a source of pressurized fluid inconjunction with the excavating machine. The present digging linetensioning device can be expeditiously installed in the conventionalsystem, and as shown for instance in FIG. 4, wherein a pump 53represents a source of pressurized fluid, say for instance, at 2000pounds per square inch pressure, and directs the pressurized fluid vialine 54 to a valve bank mechanism 56 for controlling and actuating thevarious aforementioned fluid powered actuated components of the machine.Pump 53 may be driven from power plant 14 on the machine. A line 58 istaken off of supply line 54 to the valve bank, and may be provided witha manually controlled valve '60 for controlling the flow of fluidtherethrough. A check valve 62 is provided for preventing reverse flowof fluid in line 58, and the latter is coupled to the cylinders of theaforementioned rams 48 in parallel operating relation. A line 64 mayalso be provided with a manually operated control valve 68, and a gaugemember 70 may be provided for indicating the pressure in line 64. Apressure relief valve 72 which may be adjustable and set for instance toopen at 2500 pounds per square inch, is provided in line 64 after gauge70, with line 64 then communicating with a reservoir 74.

During operation of the excavating machine, pressurized fluid willordinarily be supplied to the ram members 48, thereby applying pressureto the bearing blocks 38 mounting the truck wheels 32, and thus applyinga predetermined tension to the digging line 22 of the digging unit ofthe machine. In the event that a rock or some other obstacle becomeslodged between the chain of the digging line and the means mounting thedigging line on the machine, the pressure in the fluid distributinglines 58, 64- will rapidly increase, and the relief valve 72 will opento relieve such pressure by slackening up on the chain and thuspreventing damage to the digging line, as well as preventing stalling ofthe digging unit. During such release of excessive pressure, theobstacle may dislodge itself and thereby permit the automatic closing ofthe relief valve, or the machine operator can stop the machine andmanually remove the obstacle when he notices the pressure indicated bygauge 70 as exceeding a predetermined amount. The manual control valves69, 68 are provided for deactivating all or part of the system by eithercutting off the system entirely from the supply of pressurized fluid orby cutting off the relief valve section of the system.

It will be noted that the respective bearing block and associated ram isdisposed at an angular relationship with respect to the boom, and sodisposed as to apply a force that will be directed both upwardly andrearwardly with respect to the horizontal, and not strictly parallel tothe rear stretch 82 of the digging line, so that tension is etfectivelyapplied both to the horizontal stretch 84 of the digging line chain aswell as to the generally vertically extending stretches of chain.

From the foregoing discussion and accompanying drawings, it will be seenthat the invention provides a novel tensioning device for the diggingline of an endless digging unit, and wherein the device is operable toautomatically release the pressure, if the latter builds up beyond apredetermined maximum, so that stalling of the digging unit and/ orbreakage of the digging line will not occur. The invention also providesa fluid powered tensioning mechanism which can readily be incorporatedinto existing machines, or which may be embodied in new machines.

The terms and expressions which have been utilized are used as terms ofdescription and not of limitation, and there is no intention in the useof such terms and expressions of excluding any equivalents of any of thefeatures shown or described, or portions thereof, but it is recognizedthat various modifications are possible within the scope of theinvention claimed.

I claim:

1. In a mobile trenching machine including a generally horizontallyextending boom, means depending from said boom, first rotatable meansmounted adjacent the lower end of said depending means, second rotatablemeans rotatably mounted on said boom forwardly of said first rotatablemeans, third rotatable means mounted on said boom in rearwardly spacedrelation to said second rotatable means, an endless digging line strungabout said rotatable means and adapted to be driven by one of saidrotatable means, said digging line defining a generally invertedtriangular shape configuration in side elevation, means includingtransversely spaced bearing blocks adjustably mounting said thirdrotatable means on said boom, said boom including transversely disposedguideways therein, extending diagonally upwardly and rearwardly withrespect to said boom, each of said guideways receiving in movablerelation an associated one of said bearing blocks therein, and fluidactuated means coacting with said bearing blocks to maintain apredetermined tension in said line, said fluid actuated means extendingin a like diagonal direction as said guideways and with respect to saidboom, said guideways diverging in a downward direction with respect tothe rear stretch of said digging line.

2. A trenching machine in accordance with claim 1, wherein said bearingblocks include means thereon for guiding the bearing blocks in theirmovement lengthwise of said guideways.

3. In a mobile trenching machine including a generally horizontallyextending boom, an endless digging unit supported rearwardly of saidtrenching machine adjacent one end of said boom, a plurality of spacedrotatable means mounted on said boom, an endless digging line strungabout said rotatable means and adapted to be driven by one of saidrotatable means, said digging line including a generally horizontallyextending stretch and a pair of generally vertically extending stretchesextending downwardly toward one another from said horizontally extendingstretch defining a generally inverted triangular shaped configuration inside elevation, adjustable bearing means mounting the rearwardmost ofsaid rotatable means on said boom, hydraulic ram means coacting withsaid adjustable bearing means and extending diagonally upwardly andrearwardly from said boom generally intermediate said horizontallyextending stretch and the rearwardmost of the associated one of saidvertically extending stretches, and fluid control means operablycoacting with said ram means for selectively maintaining a predeterminedtension in said horizontal and vertically extending stretches and forautomatically releasing tension from said stretches when the tension inthe digging line exceeds a predetermined value.

4. A trenching machine in accordance with claim 3, wherein said fiuidcontrol means includes a fiuid distributing line connected to said rammeans adapted for connection to a source of pressurized fluid, a checkvalve in said fiuid distributing line for preventing reverse flow offluid from said ram means, and relief valve means disposed intermediatesaid check valve and said ram means for limiting the maximum fluidpressure that may be applied in said fluid distributing line.

5. A trenching machine device in accordance with claim 4 including amanually operated control valve disposed intermediate said relief valvemeans and said ram means for deactivating said relief valve means.

6. A trenching machine device in accordance with claim 4 wherein apressure indicating gauge member is disposed in said distributing lineintermediate said ram means and said relief valve means.

References Cited in the file of this patent UNITED STATES PATENTS794,624 Hoadley July 11, 1905 2,782,534 Wall Feb. 26, 1957 2,818,311Ashley Dec. 31, 1957 2,998,998 Hyler et al Sept. 5, 1961 FOREIGN PATENTS1,095,681 Germany Dec. 22, 1960

1. IN A MOBILE TRENCHING MACHINE INCLUDING A GENERALLY HORIZONTALLYEXTENDING BOOM, MEANS DEPENDING FROM SAID BOOM, FIRST ROTATABLE MEANSMOUNTED ADJACENT THE LOWER END OF SAID DEPENDING MEANS, SECOND ROTATBLEMEANS ROTATABLY MOUNTED ON SAID BOOM FORWARDLY OF SAID ROTATABLE MEANS,THIRD ROTATABLE MEANS MOUNTED ON SAID BOOM IN REARWARDLY SPACED RELATIONTO SAID SECOND ROTATABLE MEANS, AN ENDLESS DIGGING LINE STRUNG ABOUTSAID ROTATABLE MEANS AND ADAPTED TO BE DRIVEN BY ONE OF SAID ROTATABLEMEANS, SAID DIGGING LINE DEFINING A GENERALLY INVERTED TRIANGULAR SHAPECONFIGURATION IN SIDE ELEVATION, MEANS INCLUDING TRANSVERSELY SPACEDBEARING BLOCKS ADJUSTABLY MOUNTED SAID THIRD ROTATABLE MEANS ON SAIDBOOM, SAID BOOM INCLUDING TRANSVERSELY DISPOSED GUIDEWAYS THEREIN,EXTENDING DIAGONALLY UPWARDLY AND REARWARDLY WITH RESPECT TO SAID BOOM,EACH OF SAID GUIDEWAYS RECEIVING IN MOVABLE RELATION AN ASSOCIATED ONEOF SAID BEARING BLOCKS THEREIN, AND FLUID ACTUATED MEANS COACTING WITHSAID BEARING BLOCKS TO MAINTAIN A PREDETERMINED TENSION IN SAID LINE,SAID FLUID ACTUATED MEANS EXTENDING IN A LIKE DIAGONAL DIRECTION AS SAIDGUIDEWAYS AND WITH RESPECT TO SAID BOOM, SAID GUIDEWAYS DIVERGING IN ADOWNWARD DIRECTION WITH RESPECT TO THE REAR STRETCH OF SAID DIGGINGLINE.